Vaporizing type oil burner



Feb. 11, 1958 Filed Nov. 30, 1953 J. W. MILLER ET AL VAPORIZING TYPE.OIL BURNER 4 Sheetg-Sheet l INVENTORS JOHN W M/Luse c3 FBEDEP/CK ISro/vsv,

477'OENEV2 J. w. MILLER ETAL VAPORIZING TYPE OIL BURNER Feb. 11, 1958 4Sheets-Sheet 2 Filed NOV. 30, 1953 44 Fla, 5

K. m w p M55 Wu a N NE DA 0 0. Ha W @F A Feb. 11-, 1958 i J. w. MILLERET AL 2,822,356 VAPORIZING TYPE OIL BURNER Filed Nov. so. 1953 4Sheets-Sheet s Fla. 8'

INVENTORS JOHN W MALE? 3- ATTOENEYS Feb. 11, 1958 J. w. MILLER ET AL 2,

VAPORIZING TYPE OIL BURNER Filed Nov. 30, 1953 4 Sheets-Sheet 4INVENTORJ JOHN M/ MILLER &

BY FQEDEk/CK Z STONE).

VAPORIZING TYPE OIL BURNER John W. Miller and Frederick T. Stoney,Lansing, Mich., assignors to Motor Wheel Corporation, Lansing, Mich., a,corporation of Michigan Application November 30, 1953, Serial No.394,934

17 Claims, (Cl. 158-91) This invention relates to vaporizing type oilburners and more particularly to a burner structure for stabilizing andimproving the combustion in the burner at the pilot fire stage ofoperation.

'In vaporizing pot type burners one of the problems that arises is theinevitable production of eddy currents. When the burner is operating atpilot fire, vertical air currents in the burner result from thetemperature differential in the burner and in turn produce horizontalcross currents which are both radial and circumferential. These eddycurrents, both vertical and horizontal, tend to produce unstablecombustion and also tend to extinguish the pilot flame so that itbecomes necessary to increase the minimum amount of fuel admitted to theburner at pilot operation to maintain combustion. Pilot flamestabilizers,

that is, burner arrangements for producing a stable and clean pilotflame, have heretofore been proposed which remedy this problem to someextent. For example, in the Miller et a1. Patent 2,448,148 there isdisclosed a pilot stabilizer which tends to confine the burning at thefuel inlet opening. Experience has shown that although the arrangementshown in said Miller et al. patent tends to stabilize the flame at pilotoperation, nevertheless, the combustion at pilot fire operation withsuch an arrangement is sometimes ineflicient and tends to produce asmoky flame.

it is an object of this invention to improve upon the arrangement shownin said Miller et a1. patent and more specifically it is an object toadvantageously utilize the eddy currents naturally occurring in theburner for the purpose of improving combustion at pilot fire stage ofoperation.

In the drawings:

Fig. 1 is a fragmentary vertical sectional view of a burner embodyingthe present invention.

Fig. 2 is a perspective view of one of the shield members of the pilotfire stabilizing structure.

Fig. 3 is a perspective view of the other shield member of the pilotfire stabilizing structure.

Fig. 4 is a sectional view along the line 44 of Fig. 1. Fig. 5 is afragmentary sectional view of a burner embodying a modified form ofpilot fire stabilizer structure of this invention.

Fig. 6 is a sectional view along the line 6-6 of Fig. 5.

Fig. 7 is a fragmentary sectional view of a burner showing anothermodified form of pilot fire stabilizer ,of this invention. i

Fig. 8 is a sectional view along the line 8-8 of Fig. 7.

Figs. 9, 10 and 11 are perspective views of the pilot stabilizerarrangements shown in Figs. 1, 5 and 7, respectively.

Referring to the drawings, there is shown in Fig. l a heating structurewhich includes a pot type oil burner generally designated 10. The burner10 includes a cup shaped bottom wall portion 12 which is flanged aroundits upper edge to telescopically receive a tubular side side wall member14. Adjacent its upper end, side wall 14 is provided with acircumferential bead 16 which has 2,822,866 Patented Feb. 11',- 1958 aclose fit with a casing 18 which defines in the space above burner 10 acombustion chamber 20. The side wall 14 of the burner is provided with aplurality of air inlet openings 22. The openings 22 arecircumferentially spaced and preferably arranged in vertically spacedrows as indicated. An inclined bafiie Z4 is arranged within the burner.Baffle 24 is provided with a central opening 26 and divides the burnerinto an upper chamber 28 and a lower chamber 30.' 'It will be observedthat some of the air inlet openings 22 communicate with chamber 30 andothers of the openings 22 "communicate with the chamber 28. At its upperend burner 10. is provided with a centrally apertured top wall 32 onwhich is positioned an anti-explosion bafile 34. The sidewall 14 of theburner is also provided with inlet openings 36 and 38 for the admissionof secondary air above the plane of top wall 32. Fuel is admitted to theburner through an inlet pipe 40 and an inlet opening 42 at one side ofthe burner adjacent the bottom wall 12. Immediately adjacent the inletopening 42 the bottom wall 12 of the burner is provided with a recess orpocket 44 which is arranged to fill with oil before the oil flows overthe bottom wall 12 of the burner. The improvement of the presentinvention resides in the provision of an arrangement for producing aclean, stable flame adjacent the inlet opening 42 when fuel is being'admitted to the burner in a minimum amount corresponding to pilot fireoperation. The structure provided for this purpose may take severalforms, the preferred structure being shown in Figs. 1 through 4. Thepilot stabilizer of preferred construction comprises two shield members46 and 48. The member 46 is fashioned with two generally convergingbafiles or side walls 50, the upper edges of which are connected by atop wall 52. The member 46 is also provided with a rear wall 54 which isarcuately shaped in horizontal sectionto conform with the contour of thecylindrical wall portion 56 of the cup shaped member 12 of the burner.The rear wall 54 of member 46 is provided with a central opening 58 atits lower edge which is adapted to register with the inlet opening 42when the shield 46 is positioned in the burner as shown in Fig. 1.

The member 48 of the pilot stabilizer includes a pair of upstandingbaflles 60, the upper edges of which are spanned by a top wall 62. Topwall 62 has a rear arcuate edge 64 which conforms with the curvature ofside wall 14 of the burner at the portion thereof adjacent inlet opening42 just below the inclined baffle 24. Top wall 62 is preferably inclinedrelative to the lower edges of upstanding baflles 60 and the baflies 60are dimensioned in height such that the member 48 may be slipped intoposition in the burner with the baffles 68 supported on the bottom wall12 of the burner and the top wall 62 fitting flush against the undersideof baflie 24. It will be observed that the depth of top wall 62 in aradial direction or a direction from front to back is greater than thedepth of the baffles 60 in the same direction. Therefore, as shown moreclearly in Fig. 4, when the member 48 is positioned within the burnerwith the top wall 62 underlying bafiie 24 and with the edge 64 thereofengaging the side wall of the burner, the baffles 60 are spaced radiallyinwardly from the side wall of the burner. It will also be noted thattop wall 62 and bafiles 60 extend radially inwardly beyond top wall 52and side walls 50 of shield member 46.

On its bottom side, top wall 62 is provided with a centrally arranged,vertically depending lug or' wall 66 which extends from the straightedge 68 to the arcuate edge 64. The top wall 52 of member 46 is providedwith a notch 70 at its inner edge in which a projection 72 at the lowerend of lug 66 is arranged to engage to hold the member the burner.

It will be observed that in the operative position of members 46 and 48,the chamber 74, defined by the walls 50, 52 and 54 of member 46 and thebottom wall 12 of the burner, has an opening 75 at its radial inner orfront end. Furthermore, the walls 50 cooperate with the baffles 60 toprovide radial passageways 76, the outer or rear ends of whichcommunicate with the burner through the spaces 78 between the rearvertical edges of the baffles 60 and the side wall 14 of the burner. Theinner or front ends of passageways 76 communicate with the burnerthrough the openings 79. The wall 66, of member 48 forms a radiallyarranged central partition extending vertically betwen the top walls 52and 62. At its outer vertical edge, wall 66 is shaped to interfit theside wall 14 of the burner. g

' The operation of the burner provided with the pilot stabilizer,arrangement described above is as follows: Fuel flows into the burnerthrough the inlet pipe 40 and through openings 42 and 58 and into theoil pocket 44. The oil pocket 44 is shielded from the burner by themember 46 so that communication between the interior of the burner andthe oil pocket 44 is established only through the .open inner end 75 ofthe shield 46. The member 46 thus forms the shielded chamber 74 in whichthe oil in pocket 44, after being ignited, is vaporized. The heat ofcombustion induces vertical air currents in the burner which in turnproduce a flow of air across the bottom wall 12 of the burner and intochamber 74. This current of air, which is represented by the arrows 80inFig. 1, mixes with the oil vapors in chamber 74, thereby forming a veryrich mixture of air-oil vapors which flows out of the chamber 74 alongthe upper edge of opening 75. The air which mixes with the vapors inchamber 74 is of insufficient amount to form a burning mixture and theserich vapors are diluted by the currents of air flowing radially inwardlyon either side of partition 66 to provide a combustible mixture whichburns along the upper edge of opening 75 of chamber 74. This additionalair flows into the space between walls 52 and 62 through the openings 22in that portion of the side wall 14 of the burner that extends betweenthese two vertically spaced walls. As the amount of fuel admitted to theburner is increased, the heat generated in the burner likewise increasesand the vertical and horizontal eddy currents of air are also increased.The air that circulates horizontally in the burner enters thepassageways 76 through the openings 78 and flows radially inwardlytoward the center of the burner. This flow of air through thepassageways 76 tends to draw oil vapors out of mixing chamber 74 andmixes therewith to initiate burning also at the openings 79 at the innerends of passageways 76. With a further increase in the amount of fueladmitted the flame gradually moves out into the burner and the bottom ofthe burner is filled with flame. The flame gradually moves upwardly inthe burner as the rate of fuel admission is increased until at high firestages of combustion burning takes place in combustion chamber 20.

In a typical construction with a burner having a diameter of abouttwelve inches with the shield member 46 being about one andthree-quarter inches high and two ane one-half inches wide at its frontor inner end, and with shield 48 being about three and one-half incheshigh and about three and three-eighths inches wide at its front end, theside baflles 60 being spaced about onehalf inch inwardly from the sidewall 14 of the burner, a flame along the upper edge of opening 75 isinitiated at a flow of about 60 cc. per hour which is considered pilotfire. At a flow of about 85 cc. per hour the circumferential aircurrents moving through spaces 78 and then radially inwardly throughpassages 76 pick up enough oil vapor as they flow past the opening 75 tostart burning at the openings 79 also. The flame tends to stay at theopenings 79 and along the upper edge of the opening 75 until a flow ofabout 180 cc. per hour is reached when it moves out into the burner, asexplained above.

. 4 In Figs. 5 and 6 there is shown a simplified form of pilotstabilizer construction. In this arrangement the use of two shieldmembers, such as shown at 46 and 48 of the previous embodimentdescribed, is avoided; and in place thereof, a single shield member 82is employed. The member 82 is preferably fashioned as a casting hav ingtwo sets of side wall baflles 84 and 86 and an inclined top wall 88. Theside wall baffles 84 and 86 are dimensioned in height so that whenshield member 82 is in the operative position within the burner, topwall 88 fits flush beneath inclined baflie 24 within the burner. Topwall 88 has a substantially straight front or inner edge 90 and an.arcuate rear or outer edge 92 which interfits with the arcuate sidewall14 of the burner. The side wall baffles 84 .arearranged to extendgenerally radially inwardly from the side wall 14 of the burner whereasthe side wall baffles 86 are spaced radially inwardly from the side wall14 of the burner to provide openings 94 for radial passageways 96 whichdischarge into the burner at their inner ends through openings 96.

The arrangement shown in Figs. 5 and 6 operates generally the same asthat shown in Figs. 1 through 4. However, since the openings 22 in theside wall of the burner communicate directly with the mixing chamber 98which is defined by the bottom and side walls 14 and 16 of the burnerand the walls 84 and 88 of the shield members 82, burning takes placeWithin the chamber 98 at a relatively low rate of fuel admission and theflame gradually moves out to the openings 96 as the rate of fueladmission is increased. In Figs. 7 and 8 there is shown another modifiedform of pilot stabilizer construction of this invention. This form ofconstruction differs from that shown in Figs. 5 and 6 primarily in thatthe single shield member 100 is of less height than shield member 82(Fig. 5) and the top wall 102 thereof is flat rather than inclined. Alsoin the arrangement shown in Figs. 7 and 8, the two inner radiallyextending side walls 104 are spanned across their rear vertical edges bya rear wall 106. The other two radially extending side walls 108 arespaced radially inwardly of the side wall 14 of the burner to provideinlet openings 110 to the radial passageways 112 which communicate withthe burner at their inner ends through the openings 114. The shieldmember 100 is retained in position by means of a lug 116 depending fromthe lower side of baflle 24 and having a projection 118 at the lower endthereof which engages in a slot 120 formed in thefront edge of the topwall 102.

In operation the form of construction shown in Figs. 7 and 8 isgenerally the same as that shown in Figs. l through 4. It will beobserved that the mixing chamber 122 is open only at its front or innerend. Thus, as isthe case with the form of construction shown in Figs. 1and 4, insuflicient air is admitted to the chamber 122 to form a burningmixture within the chamber and the flame is initiated along the inneredge of top wall 102. The reason for the initiation of combustion atthis point rather than within the chamber 122, as is the case with thearrangement shown in Figs. 5 and 6, is twofold. In the first place,chamber 122 is of substantially less height than the chamber 98. Thisprevents the radial air currents from penetrating all the way intochamber 122. Also, since the air inlet openings 22 in the side wall 14of the burner are disposed above top wall 102 and the rear wall 106prevents leakage of air into chamber 122 from the rear side thereof,insufiicient air enters chamber 122 to form a combustible mixture. Thus,at low rates of fuel admission the flame is initiated along the inneredge of wall 102 and when the fuel is admitted at a higher rate thecircumferential air currents produced by the greater temperaturedifferential in the burner flow radially inwardly through passageways112 and pick up enough oil vapor to start burning also at the openings114.

Thus, it will be seen that We have provided a pilotifirestabilizingstructure in a vaporizing pot type burner which is designed to actuallyutilize the eddy currents produced in the burner advantageously tor thepurpose or stabilizing and improving the combustion at pilot fire stagesof operation.

we claim:

1. ln a vaporizing pot type burner having a bottom wall, a tubular sidewall provided with circumferentially spaced air inlet openings and afuel inlet opening at one side of said burner ad acent said bottom wall,means for improving combustion in said burner at pilot tire stage oroperation comprising, means within the burner and cooperating with thebottom wall thereof to detine a relatively small chamber in the burnerwhich extends radially inwardly trom the side wall or the burner and isin open communication with the burner at its radially inner end, saidchamber being located so that said fuel inlet opens thereinto and beinggenerally impertorate except tor said open end thereoi, said chamberhaving a radially extending side wall denmng, at least in part, the openend or the chamber, a radially extending wall in said burner closelyspaced from and cooperating with said side wall or the chamber to form aradially inwardly extending passageway communicating with the interiorof the burner at its radially outer end ad acent the side wall of theburner and at its radially inner end adjacent the open end of saidchamber.

2. The combination set torth in claim 1 wherein said chamber has a topwall extending generally horizontally and radially inwardly from theside wall of the burner and including another wall in said burnerextending generally horizontally and radially inwardly from the sidewail of the burner, said last mentioned wall being spaced above and adacent said top wall oi said chamber, at least some or said air inletopenings in the burner side wail being located at the portion of saidburner side wall extending between said two generally horizontallyextending walls.

3. in a vaporizing pot type burner having a bottom wall, a tubular sidewall provided with circumterentially spaced air inlet opemngs and a tuelinlet opening at one side ot said burner ad acent said bottom wall,means for improving combustion in said burner at pilot fire stage oroperation comprising, means including a pair of side walls and a topwall cooperating with the bottom wall of the burner to define arelatively small chamber in said burner ad acent the burner side wall,said chamber being located so that said tuel inlet opens thereinto, saidside walls extending generally radially inwardly from the burner sidewall and said top wall extending between and connecting the upper edgesof said side walls, the radially inner end of said chamber being in opencommumcation with the interior of said burner and a pair of generallyradially extending batfles positioned exteriorly of said chamber oneadjacent to and spaced from each of said side walls of said chamber,said bafiies cooperating with said side walls of said chamber to formgenerally radially extending passageways along opposite sides of saidchamber, said passageways communicating with the interior of the burneradjacent their radially outer ends adjacent the side wall of the burnerand at their radially inner ends adjacent said open end of said chamber,said baflles extending radially inwardly a greater extent than said sidewalls of said chamber.

4. The combination set forth in claim 3 wherein said side walls of saidchamber and said baflies are disposed in converging, non-intersectingrelation.

5. The combination set forth in claim 3 wherein said battles are spacedfrom the burner side wall.

6. The combination set forth in claim 3 wherein the outer edges of saidside walls are in close engagement with the side wall of the burner, theportion of said burner side wall extending between said last mentionededges providing a wall at the radially outer end of said chamber.

7. The combination set forth in claim 3 wherein said chamber includes arear wall connecting the radially outer end of the chamber side wallsand extending upwardly from substantially the lower edges of said sidewalls to said top wall.

8. The combination set forth in claim 3 wherein said top wall connectswith the upper ends of said baflles.

9. The combination set forth in claim 3 wherein some of said air inletopenings communicate directly with said chamber.

10. The combination set forth in claim 3 including a generallyhorizontal wall extending radially inwardly from the burner side walland spaced above said top wall.

11. The combination set forth in claim 10 wherein said air inletopenings are disposed exclusively above the plane of said top Wall.

12. The combination set forth in claim 10 including a vertical partitionextending radially between said last two mentioned walls along a linegenerally centrally of said top wall.

13. The combination set forth in claim 10 including a vertical partitionextending radially inwardly from the burner side wall between said topwall and said generally horizontal wall along a line extending generallycentrally of said top wall.

14. The combination set forth in claim 10 wherein said top wall connectswith the upper ends of said baffies.

15. The combination set forth in claim 10 wherein said generallyhorizontal wall extends between and connects the upper ends of saidbaflles.

16. The combination set forth in claim 10 wherein said generallyhorizontal wall extends radially inwardly beyond said top wall.

17. The combination set forth in claim 10 including a dependingpartition on said horizontally extending wall, said partition extendingradially inwardly from the side wall of the burner, the lower end ofsaid partition and said top wall being provided with interengaged lugand socket members.

References Cited in the file of this patent UNITED STATES PATENTS2,316,227 Donley Apr. 13, 1943 2,452,924 Greer Nov. 2, 1948 2,470,570Miller et al May 17, 1949 2,474,530 Huston June 28, 1949 2,537,966Cargile et a1. Jan. 16, 1951 2,602,495 Greer July 8, 1952 2,748,847Gilmore et a1. June 5, 1956

